Few Child Psychiatry Clinics have any established mechanism for routinely assessing the effectiveness of their clinical work. A proposal is submitted to test a systematic and relatively inexpensive technique - using previously standardized instruments - for their ability to measure behavioural improvement in children receiving a wide range of psychiatric interventions in a general clinic setting. Additional aims will be to replicate validity and reliability of the standard instrument for broad diagnostic groups, and to examine both the patient and the treatment characteristics associated with therapeutic change. 1000 unselected patients will enter the study over a two-year period. Behar Preschool Behavior Questionnaires and Conners Parent and Teacher Questionnaires will be tested for test-retest reliability on this broad diagnostic group. Questionnaires will be tested for validity as detectors of both presence and severity of psychopathology and specificity for diagnostic groups by comparing correlation of questionnaire ratings with ratings derived from extensive standardized clinical assessment. The questionnaires' sensitivity to detecting clinical change, as compared with clinicians' ratings, will be assessed. Pilot data will be obtained on the relationship of diagnostic, treatment, demographic, and sociocultural variables to the questionnaires' sensitivity to detect presence of psychiatric disorder and to detect change. If this approach to clinical evaluation can be shown to be effective it will be of great potential use to public health administrators, clinic directors and clinics alike.